中文摘要：

生态系统对人类活动的承受能力是土地管理的一个核心问题,一般情况下旅游活动与自然环境保护间存在着明显的冲突。本研究结合六盘山人类旅游活动季节性规律,以野荷谷、小南川、梁殿峡3个核心景区中易受旅游干扰的典型植被类型为对象,在植物初春萌芽（5月）至生物量最大期（8月）通过践踏实验,模拟典型植被类型和主要植物物种对人类旅游践踏的敏感性（相对敏感性和绝对敏感性）,并构建三类（抗性、耐性和弹性）指数进行定量表征。研究结果表明：①从3种植被类型的相对敏感性看,其植被类型的抗性、耐性和弹性间具有一致性,其大小顺序为梁殿峡高山草甸植被〉野荷谷华北落叶松林下植被〉小南川乔灌草植被,3种植物类型抗性分别为59.62%、37.86%、14.16%,耐性指数为90.51%、84.217%、26.80%,弹性指数为78.017%、66.04%、15.35%;②从各植被类型组成物种的绝对敏感性看,小南川景区表现最为敏感,消失物种最多（6种）,野荷谷次之（5种）,梁殿峡最少（2种）;三个景区中消失物种主要为山荆子、龙牙草、华北落叶松幼苗、李幼苗、莓叶委陵菜和豆科野豌豆;③研究结果表明,处于初春萌芽阶段的景区植物幼苗,对人类践踏具有高度的敏感性,旅游践踏不仅当时造成部分植物消亡,也对植物后续的生长产生较大负面作用,进而影响到旅游区生态系统正常的发展演替。

英文摘要：

The carrying capacity of ecological system is a core problem for the land management, because there is a obvious conflict between tourism activities and natural environment. Three typical vegetations, which are edelweiss meadow in Liangdianxia, larch in Yehegu and ？？ in Xiaonanchuan, are selected in this paper, since these are the core tourism areas in Liupan Mountain Reserve. Tourism activities simulation is conducted from the sprout period in spring （in May） to the period with maximum biomass （in August） to study the dynamical responses of the three vegetation types. Experimental treading is conducted upon the three vegetation types in five separate mountain regions. Each type is tread upon for 0-500 times. Vegetation responses to the treading are assessed by evaluating the vegetation cover 2 weeks after and three months after the treading tests. Based on the changes of vegetation cover in the different stages, the sensitivity of three vegetations to the tourist activities can be evaluated by three indices, which are the tolerance index, the resistance index and the elasticity index. The results of this study show that： 1） In terms of relative sensitivity, all the sensitivity indices respond consistently. The sensitivity level ranking of the three vegetations is： Liangdianxia ranks first and Xiaonanchuan is the last. However, vegetation in Xiaonanchuan is especially sensitive to human treading. 2） In terms of absolute sensitivity, the species in the three regions have different vegetation level and therefore, the sensitivity level is different too. The sensitivity level in Xiaonanchuan ranks first, because nearly 6 species disappear in the treading test period. The number of disappeared species in the Yehegu is 5 and in Liangdianxia, it is 2. The disappeared species in the three regions are mainly Baccatae, Agrimonia L. baby, Prunus padu, Agrimonia pilosa Ledeb of Rosaceae and Vicia sepium Linn of Leguminosae. Also, the coverage rate of some other species reduces due to the treading. These r